Designing a social software based intranet within an organisation involves a change process. You need to adjust and promote the organisation from loosly joined entities to decentralized but still densly knitted nodes in a collective brain. Those things do not happen by just implementing a software solution.
Most of your energy and capital needs to go into conceiving such a virtual organization.

During an information architecture on an enterprise Social Software solution Sebastian Fiedler happen to conceive of those tools as diagnostic instruments.

An interesting point although it only makes sense if you understand it as a starting point for building a virtual company. The latter means in general that you have to start a change process.